The invention relates generally to fluid pump apparatus, and more particularly to a suction manifold or fluid intake base connecting a pump to a motor, particularly in a deep well pump unit.
It is conventional in submersible pump units to couple the motor to the intake end of an in-line pump by means of a base member, made of cast iron for example, having lateral fluid inlet openings surrounding an axial opening through which the rotor and pump drive shafts are coupled. Besides the necessary passageways in the configuration of the pump-motor base, it is also desirable for the base to be as corrosion resistant as possible while having high strength and especially high resistance to impact. Because of its intermediate location between the pump and motor housings, the base potentially presents a weak link easily fractured by dropping one end of the pump unit during handling or shipping, for example. However, corrosion resistant materials which have good strength properties like brass or stainless steel are costly.
Examples of prior art base units of general interest are found in U.S. Pat. Nos. 2,960,937 to Wright et al, 3,234,886 to Leff and 3,437,045 to Tremain. A plastic base with an integral strainer screen is shown in U.S. Pat. No. 3,521,970 to Deters assigned to the asignee of the present application. While the plastic base in the latter patent provides many desirable qualities, the base itself is placed under axial tension because of the weight of the motor components suspended therefrom. The base or suction manifold is threadably received in the end of the pump housing and the opposite end of the base is bolted to the motor. U.S. Pat. No. 3,188,968 to McMahan shows a different type of pump unit, referred to as a close-coupled pump unit, having a thin back plate member 20, as shown in FIGS. 1 and 3, which appears to be placed in compression by means of long capscrews or tie rods 23. The back plate is not plastic, however, and apparently has no intake openings.